A DefinitionContainer containing the metadata of all parameters in
the operation. There should be one ParameterDefinition object
in the DefinitionContainer containing metadata for each parameter.
If there are no paremeters, or if the operation is a common
operation, an instance of EmptyDefinitionContainer
should be returned.

getDefinitionParent

Returns the parent of this metadata definition, which is the Definition
that contains this Definition. For example, the parent of an AttributeDefinition
could be a StructureDefinition if the attribute is contained in the structure.